A) Field of the Invention
The present invention relates to a semiconductor device manufacture method, and more particularly to a semiconductor device manufacture method in which an insulating film having a high dielectric constant such as zirconia (ZrO2) and hafnia (HfO2) is formed on a semiconductor substrate and partially etched.
B) Description of the Related Art
Zirconia and hafnia have a dielectric constant higher than silicon oxide and have been paid attention as the material of a gate insulating film of next generation MISFETs. In manufacturing MISFET, the gate insulating film left on the surfaces of source and drain regions is required to be removed in order to form metal silicide films on the surfaces of the source and drain regions.
Since zirconia and hafnia are chemically stable to a large degree, it is difficult to etch it by a wet process. It is also difficult for reactive ion etching (RIE) to have a high etch selection relative to both silicon oxide of an element separation region and silicon of a substrate and a gate electrode.